With summer quickly approaching, sunscreen is a valuable tool for skin cancer prevention - but only if its used correctly. When applying sunscreen, many people make mistakes that could compromise their protection from the suns harmful ultraviolet rays, which may increase their risk of skin cancer.
Some of those mistakes are highlighted in research published in theJournal of the American Academy of Dermatology.Researchers observed 2,187 people using sunscreen over the course of 93 hours. Only one-third - 33 percent - of people applied sunscreen to all exposed skin, and just 38 percent were wearing sun-protective clothing, hats or sunglasses. Additionally, use of the free sunscreen dispensers decreased significantly on cloudy days.
These results highlight some of the ways people use sunscreen incorrectly, says study author and board-certified dermatologist Ingrid Polcari, MD, FAAD, an assistant professor in the department of dermatology at the University of Minnesota Medical School in Minneapolis. To get the best possible sun protection, its important to wear protective clothing, such as long-sleeved shirts and pants, and to apply sunscreen to all exposed skin, not just your face and arms. Everyone should apply sunscreen every time they go outside. Even on cloudy days, up to 80 percent of the suns harmful UV rays can reach your skin.
Research has shown that women are more likely than men to use sunscreen, but its vital that men use it too, says board-certified dermatologist Darrell S. Rigel, MD, FAAD, a clinical professor in the Ronald O. Perelman Department of Dermatology at New York University. Men over 50 have a higher risk than the general population of developing melanoma, the deadliest form of skin cancer, and UV exposure is the most preventable skin cancer risk factor, so its important for men of all ages to protect themselves from the suns harmful rays by seeking shade, wearing protective clothing and applying sunscreen.
Tips For Choosing A Sunscreen
Choose a sunscreen with an SPF 30 or higher.While no sunscreen can filter out all of the suns UVB rays, SPF 30 sunscreens block 97 percent of the suns UVB rays. Look for the words broad spectrum.This means the sunscreen will protect against both UVA rays - which cause premature skin aging - and UVB rays - which cause sunburn. Both types of UV rays can lead to skin cancer.
Apply sunscreen 15 minutes before going outside. Most sunscreen takes time to be absorbed for it to work. Reapply sunscreen every few hours and especially after swimming and toweling off. It wears off, even if the label says waterproof.
UVA light penetrates glass, so apply sunscreen before a car ride, even if youre going garage to garage. For children between six months and two years, use a sunscreen that works as a physical blocker. Check the label. Older children can use the same sunscreen that adults use.
Regardless of sunscreen use, the best protection is to avoid the sun as much as possible by wearing wide-brimmed hats, sun-protective clothing, and staying in the shade whenever possible, he says.
Look for the words water resistant.No sunscreen is completely waterproof, but water-resistant sunscreens can provide protection for wet or sweaty skin for 40 or 80 minutes, as indicated on the label. All sunscreens should be reapplied every two hours, or after swimming or sweating.
For sensitive skin, choose a sunscreen with the active ingredients zinc oxide or titanium dioxide.Those with sensitive skin also should avoid sunscreens that contain fragrance, oils and para-aminobenzoic acid, also known as PABA. The best type of sunscreen is one youll use, Dr. Rigel says, so find one you like and apply it to all exposed skin before heading outside.
Spread On The Sunscreen
No matter what the color of your skin, UTSouthwestern cancer experts recommend wearing sunscreen. Anyone and everyone who is going to be outside for any period of time should be wearing sunscreen to protect against skin cancer, addsDr. Rajiv Nijhawan, a dermatologist with theHarold C. Simmons Comprehensive Cancer Centerat UTSouthwestern Medical Center. While skin cancer is less common in people of color, when it is found, it is often diagnosed at later stages and can be more serious.
Its also important to use a broad-spectrum sunscreen. The SPF grading system only covers UVB light, but UVA light also causes skin cancer, including melanoma, says Dr. Nijhawan, Assistant Professor of Dermatology. The words broad spectrum indicate that protection is provided for both UVB and UVA light.
Is Cyanobacteria The Future Of Sunscreen?
Sunscreens and moisturizers derived from biological sources such as cyanobacteria could represent a safer alternative to current, synthetically produced cosmetics, research published recently in theEuropean Journal of Phycologysuggests.
Using organic matter to develop sunscreens could lessen the risk of adverse side effects, such as contact sensitivity and estrogen mimicking, and help prevent potentially harmful chemicals from entering the environment, say lead author Peyman Derikvand of the University of Isfahan, Iran, and colleagues from Swansea and London.
The use of biological compounds has many potential advantages for the cosmetics industry, one of which is the organism's ability to self-renew and reproduce, ensuring that supplies are sustainable. This is especially true for photosynthetic organisms that require only light energy, carbon dioxide and basic nutrients.
One group of such organisms, cyanobacteria, could have great potential as a source of cosmetic products for sunscreens and moisturizers because some of its species live in extremely arid habitats and thus produce compounds that give them the ability to cope with both high UV radiation and extreme desiccation. These compounds include mycosporine-like amino acids (MAAs) and scytonemin, which provide strong screening protection from longwave and shortwave UV radiation respectively. Such natural photoprotectants could be good candidates as alternatives to synthetic UV filters.
In addition, extracellular polymeric substances (EPS) derived from cyanobacteria appear to be much more effective at retaining moisture than EPS from conventional moisture-preserving materials, such as urea, glycerin and propylene glycol, currently used in cosmetics.
Cyanobacteria have higher photosynthetic and growth rates than more complex plants, simple nutritional requirements, and the ability to grow under closed cultivation systems that do not compete with agriculture. However, economic and sustainable production of these bio-compounds at the large scales required by the cosmetic industry is a key challenge.
"As we move into an era where we are turning to nature to replace synthetic chemicals, industry is being driven to look to natural product alternatives, says author Carole Llewellyn, Associate Professor in Applied Aquatic Bioscience. Cyanobacteria, tiny photosynthetic microbes, offer new potential. One suite of compounds are synthesized to protect against damaging ultraviolet and intense sunlight. These compounds offer many advantages over current synthetically derived sunscreens."
"On-going research into the intensive cultivation of photosynthetic microorganisms in photobioreactors is bringing new understanding in terms of design, operation and scale-up, and will steadily improve both the economics and feasibility of industrial production of cyanobacteria," says Llewellyn.
Technical improvements coupled to market demand should see the increasing application of cyanobacterial metabolites in the cosmetics sector, the authors conclude.
What About The New DNA Sunscreen?
Researchers at Binghamton University, State University of New York have developed a coating made out of DNA that gets better at protecting skin from ultraviolet light the more you expose it to the sun, and it also keeps your skin hydrated.
"Ultraviolet (UV) light can actually damage DNA, and that's not good for the skin," says Guy German, assistant professor of biomedical engineering at Binghamton University. "We thought, let's flip it. What happens instead if we actually used DNA as a sacrificial layer? So instead of damaging DNA within the skin, we damage a layer on top of the skin."
German and a team of researchers developed thin and optically-transparent crystalline DNA films and irradiated them with UV light. They found that the more they exposed the film to UV light, the better the film got at absorbing it. "If you translate that, it means to me that if you use this as a topical cream or sunscreen, the longer that you stay out on the beach, the better it gets at being a sunscreen," German said.
Slowing Water Evaporation
As an added bonus, the DNA coatings are also hygroscopic, meaning that skin coated with the DNA films can store and hold water much more than uncoated skin. When applied to human skin, they are capable of slowing water evaporation and keeping the tissue hydrated for extended periods of time.
German intends to see next if these materials might be good as a wound covering for hostile environments where you want to be able to see the wound healing without removing the dressing, you want to protect the wound from the sun, and you want to keep the wound in a moist environment that is known to promote faster wound healing rates.
"Not only do we think this might have applications for sunscreen and moisturizers directly, but if it's optically transparent and prevents tissue damage from the sun and it's good at keeping the skin hydrated, we think this might be potentially exploitable as a wound covering for extreme environments," he said.
Could Seaweed Hold Key To Environmentally-Friendly Sunscreen?
A compound found in seaweed could protect human skin from the damaging impact of the sun without causing harm to marine ecosystems. The use of sunscreens is advocated to prevent sun damage, but most formulations contain synthetic UV radiation filters that can make their way in to water systems. Many of these are not ecocompatible and may harm fragile marine life including coral, fish and microorganisms.
Scientists at King's College London extracted a mycosporine-like amino acid (MAA), known as palythine, from seaweed to test its ability to protect against UV radiation in human skin cells. MAAs are natural compounds produced in organisms that live in sunlight-rich, shallow-water environments.
Using human skin cells in a lab, researchers showed that even at very low concentrations MAA could effectively absorb harmful rays from the sun and protect the cells against UVR-induced damage. They also showed that palythine is a powerful antioxidant that could offer skin protection against oxidative stress, linked to cellular damage and photoaging.
The paper - published in theBritish Journal of Dermatology - represents a breakthrough that could help move towards the development of an ecocompatible, non-toxic, natural sunscreen that protects human skin without negative environmental effects. Further research is required in order to prove that the compound has the same properties outside of the lab environment. The European Chemicals Agency and The Environmental Effects Assessment Panel (EEAP), part of the United Nation Environment Programme (UNEP), have expressed concern about the eco-toxic effects of eight out of the 16 commonly used sunscreen filters in Europe.
MAAs, in addition to their environmental benefits, appear to be multifunctional photoprotective compounds, says lead author Dr. Karl Lawrence from St John's Institute of Dermatology at King's. They work through the direct absorption of UVR photons, much like the synthetic filters. They also act as potent antioxidants, which is an important property as exposure to solar radiation induces high levels of oxidative stress and this is something not seen in synthetic filters.
There are significant concerns that conventional sun protection products are having a negative impact on the environment, added Professor Antony Young, senior author of the paper and member of the EEAP. Our data show that, with further research and development, marine-derived sunscreens may be a possible solution that could have a significant positive impact on the health of our marine habitats and wildlife, whilst still providing the essential sun protection that human skin requires to guard against damage that causes diseases such as skin cancer.